How to continue a line when using BWT algorithm?

Question

Cryptography

With the help of direct transformation, I found the encrypted word, but I need to somehow decipher the word according to the formula how to do it, I don’t understand and can’t find information on how to do it

1) We number the letters of the row
L = “R V P G A A Y A”
( 0, 1, 2, 3, 4, 5, 6, 7)
2) Sort by alphabet and get an array of numbers T:
T = (4, 5, 7, 1, 3, 6, 2, 0)
(A A A B G Y P R)
3) We have L \u003d "R B P G A A Y A", i \u003d 6, T \u003d (4, 5, 7, 1, 3, 6, 2, 0);
We get a series of letters S: S[j]= L[T j+1[i]].
S[0]= L[T 1[6]]= L[2]=”P”;
S[1]= L[T[T[2]]]= L[T[2]]=L[7]=”A”;
S[2]= L[T[7]]=L[0]=”P”;
S[3]=
S[4]=
S[5]=
S[6]=
S[7]=
S = "PARAGUAY".

How to populate indices S[3]-S[7]